They'll never forget how you made them feel.

“People will forget what you said.. but they will never forget how you made them feel.” - Maya Angelou

Uncle John used to use this line too.

I take it as, if you’re giving a speech, years later people will definitely forget the exact words you used but they’ll remember if you made them laugh or if your gentle story made them tear up etc. And they’ll appreciate, admire and remember that about you and the speech forever.